The 250 kbps data rate covers the common industrial serial link — PLC programming ports, VFD parameter uploads, and barcode scanner connections — where 115.2 kbps is the floor and 250 kbps gives headroom for the protocol overhead.
Industrial temperature range and receiver hysteresis
The 300 mV receiver hysteresis cleans up slow-edged RS-232 signals on long cables — a common headache when a machine-tool controller is 15 metres from the gateway. The hysteresis means the receiver won't chatter on a floating or weakly driven line, which saves a software debounce timer in the UART ISR.
The MAX3232 family is a staple RS-232 interface — it has been around long enough that the pinout and function are second-source friendly, but TI is still manufacturing it.